JP2008308945A - Concrete foundation combined with tension pile, and construction method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a concrete foundation of high pull-off resistance by devising the shape and structure of piles usable in combination with the foundation even with small-scale excavation. <P>SOLUTION: At a center of an excavation hole, a connecting rod 13, a resistance plate 14 having a flat surface part at a lower end, and vertical wall parts roughly vertically erected from both side ends of it, and a coupling ring 16 at an upper end of the connecting rod 13 are provided to compose the tension pile, with a lower end installed on the flat surface part of the resistance plate 14 between the vertical wall parts. Foundation concrete 2 is then placed in the excavation to bury an upper part of the connecting rod 13 with the coupling ring 16. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a tension pile combined concrete foundation that stably supports a pillar of a building such as a steel structure and a construction method thereof.

2. Description of the Related Art Conventionally, in a steel structure in which a framework such as a warehouse is constructed of a shape steel, a pillar material is erected on a reinforced concrete foundation embedded in the ground.
Usually, a reinforced concrete foundation is laid with a quarry stone in a hole formed by root cutting, after rolling the quarry stone, throwing away concrete as needed, and then arranging the reinforced bar. , Foundation concrete is placed on quarry stone or discarded concrete. Furthermore, if necessary, a temporary frame is assembled on the foundation concrete, and a rising concrete is placed (see, for example, Patent Document 1).

In addition, although not used in general architectural design, a torsional flat bar twisted with flat bars is screwed into the ground, and the upper part of each twisted flat bar with an anchor bolt in the upper part is a concrete block containing steel frames. A construction method has also been proposed in which the foundation of the structure is constructed by solidifying with (see Patent Document 2).
JP 2000-179152 A JP 2001-323479 A

  By the way, reinforced concrete foundations as building foundations are generally designed to resist the pulling force acting on the pillars when the building receives horizontal force by the weight of the concrete and backfill soil. However, in a building where the pulling-out force of a pillar such as a brace structure is large, the foundation volume itself is inevitably increased in order to increase the weight of the foundation.

  Therefore, it is necessary to enlarge the hole formed by root cutting. Not only will the cost of excavation become high, but the disposal cost of the remaining soil will also increase. Moreover, it is a result that expense increases with arranging a lot of reinforcing bars.

  The present invention has been devised to solve such a problem, and even with a concrete foundation having a small size of root cutting, by devising the shape and structure of the combined pile, the pulling resistance The purpose is to provide a high foundation and a method of constructing it.

In order to achieve the purpose, the tensile pile combined concrete foundation of the present invention is composed of a foundation concrete and a steel tensile pile standing on the lower part thereof, and the steel tensile pile is attached to the connecting rod and the lower end thereof. A resistance plate is provided, and a connecting ring is formed on the upper portion of the connecting rod, and the upper portion of the connecting ring and the connecting rod is embedded in the foundation concrete.
Moreover, it is preferable that the connecting ring at the upper end of the connecting rod is inserted through a reinforcing bar disposed in the basic concrete.

Such a tension pile combined concrete foundation installs a tension pile in the center of the excavated root cut hole.
The pile with a resistance resistor plate according to claim 2 digs a hole using an earth auger or the like, installs the pile with a resistance resistor plate, and rolls the excavated soil several times.
The screw pile according to claim 3 is installed while being rotated to a predetermined position with a rotary tool provided with a dedicated jig.
The expandable pile according to claim 4 is driven to a predetermined position with a dedicated jig, and the resistance plate is spread and installed.
In addition, it is preferable to provide a plurality of tensile piles as described above for one foundation concrete.
After constructing these tensile piles, it is constructed by placing foundation concrete in the root cutting so as to embed the upper part of the connecting rod.
In an aspect in which a connecting ring is provided at the upper end of the connecting rod, it is preferable to place foundation concrete in the root cutting so as to embed the upper portion of the connecting rod after inserting the reinforcing bar for fixing the tensile pile into the connecting ring. .

The concrete pile combined concrete foundation of the present invention has a steel tensile pile having a very high pulling strength standing upright below the normal foundation concrete.
For this reason, it is not necessary to excavate a large root cut for constructing a large concrete foundation, and the remaining soil can be treated easily. As a result, a foundation having a high yield strength can be constructed at low cost. And pulling-out yield strength can be increased / decreased with the number of tension piles to install.
Furthermore, there are less soil disposal treatments and environmentally friendly points.
Furthermore, the drawing strength can be increased or decreased depending on the number of tension piles installed per place.

The inventors of the present invention have studied a method for constructing a foundation having a very high pulling strength as a foundation for standing a pillar in a steel structure without excavating a large root cut, and have reached the present invention.
Details will be described below with reference to the accompanying drawings.
The concrete foundation 1 combined with a tensile pile according to the present invention is composed of a foundation concrete 2 and a steel tensile pile 3 erected on the lower part thereof.

There is no need to devise any particular means for the foundation concrete itself. Similar to the normal foundation, the main reinforcement 4 and the band reinforcement 5 are arranged in order to improve the strength of the concrete foundation itself. An anchor bolt 10 for fixing the column 9 is also embedded. FIG. 1 shows a foundation having a rising portion, and shows a case where a pile with a grooved resistance plate is attached to a steel tensile pile 3. FIG. 2 shows a foundation having a rising portion and a case where a screw pile is used. FIG. 3 shows an embedded foundation without rising and a case where a pile with a grooved resistance plate is attached. Furthermore, FIG. 4 shows an embedded type foundation that also has no rise and shows an expandable pile. And 6 is a normal granite and 7 is abandoned concrete.
In the figure, 12 is a level adjusting mortar for attaching the base plate 11 horizontally, and 8 is a reinforcing bar for fixing the tensile pile of the present invention.

The steel tensile pile 3 erected at the lower part of the foundation concrete has the upper end embedded in the foundation concrete and the lower part embedded in the soil.
In order to increase the pulling resistance, various resistance plates are attached to the lower ends of the connecting rods 13 constituting the steel tensile pile 3. In the case of FIG. 1 and FIG. 3, there is provided a resistance plate 14 having a flat wall portion and a vertical wall portion that rises substantially perpendicularly from both side ends thereof, and the center of the vertical wall portion of the flat surface portion is attached to the lower end of the connecting rod.

Moreover, in the case of FIG. 2, the resistance board 15 which shape | molded the steel plate in the shape of a screw is attached to the lower end of the connecting rod 13 which comprises the steel tension | pulling pile 3. FIG.
Further, in the case of FIG. 4, two resistance plates 17 are attached to the lower ends of the connecting rods 13, and the lower ends of the auxiliary rods 18 are attached to the other ends of the resistance plates 17, and the upper ends of the two auxiliary rods 18. Are integrated at the top and connected to the intermediate portion of the connecting rod 13.
Although not shown, it is preferable that a plurality of steel tensile piles 3 each having a resistance plate at the tip are erected under the foundation concrete 2.

  As the resistance plates 14, 15, and 17, those having a larger area are preferable in terms of increasing the pulling strength. As described above, the pull-out strength of the pile is determined by the area of the resistance plate of the pile and the embedding depth. Accordingly, the pulling resistance is improved as the resistance plates 14, 15, and 17 are wider and deeply embedded. A steel plate is sufficient as a material used for the resistance plates 14, 15, and 17. In order to improve the durability, it is preferable to use a plated steel sheet, for example, a Zn-Al-Mg based plating.

  At the upper end of the connecting rod 13, a connecting ring 16 formed by bending the tip of the rod body is provided. When this coupling ring 16 is disposed in the foundation concrete, the pile fixing rebar 8 is inserted to contribute to an improvement in the pulling strength of the foundation concrete.

Next, a method for constructing such a concrete foundation combined with a tensile pile will be described by taking a pile with a grooved resistance plate 14 in FIG. 1 as an example.
The position where the concrete foundation combined with the present tension pile is constructed is confirmed, and a hole for root cutting having a predetermined size is excavated (a in FIG. 5). In the center of the hole, a hole corresponding to the size of the resistance plate 14 of the pile with the resistance plate and the length of the main body rod is mechanically using a holding scoop or mechanically using an earth auger or the like. Dig into (b in FIG. 5). In consideration of workability, it is preferable to use an earth auger.

A pile with a resistance resistor plate is installed on the bottom of the hole (FIG. 5c), and the excavated soil is backfilled (d in FIG. 5). In order to increase the pulling force of the anchor pile, it is necessary to compact the backfilled soil during backfilling.
In order to increase the compaction force, it is preferable to divide the backfilling into several times, and each time it is tamped using a square or rammer, or rammed using a dedicated tamping jig.

After constructing the tension pile, laying stones and placing discarded concrete (e in Fig. 5). After that, place reinforcement on the discarded concrete. At this time, in addition to the normal main bar and band bars, reinforcing bars for fixing the piles are separately arranged. Then, the reinforcing rod for fixing the pile is inserted through the connecting ring provided at the tip of the connecting rod (f in FIG. 5).
A base plate formwork is arranged on the bottom plate portion of the foundation portion where the bar arrangement is made (g in FIG. 5), and the bottom plate portion concrete is placed (h in FIG. 5).

After the bottom base concrete is solidified, a rising portion formwork is placed thereon (i in FIG. 5), and the rising portion concrete is placed (j in FIG. 5). Then, after the rising portion concrete is solidified, the formwork is removed (k in FIG. 5), the root hole is backfilled (l in FIG. 5), and the construction work of the concrete foundation combined with the tensile pile is finished.
In FIG. 5, the construction procedure of the foundation having the rising portion has been described. However, when constructing the foundation including only the foundation bottom plate portion without the rising portion, the steps i and j in FIG. 5 are omitted, and k After removing the formwork in this process, a pillar is erected and then backfilled.

Schematic explaining the structure of the concrete pile combined with the present invention tensile pile Schematic explaining other structure of concrete pile combined with the present invention tensile pile Schematic explaining other structure of concrete pile combined with the present invention tensile pile Schematic explaining another structure of the concrete pile combined with the present invention tensile pile The figure explaining the construction procedure of this invention tension pile combined concrete foundation

Explanation of symbols

1: Concrete foundation combined with tensile piles 2: Foundation concrete 3: Tensile piles
4: Main bars 5: Band bars 6: Granite 7: Discarded concrete 8: Reinforcing bars 9: Pillars 10: Anchor bolts 11: Mortar for level adjustment
12: Base plate 13: Connecting rod 14, 15, 17: Resistance plate 16: Coupling ring

Claims (8)

  A concrete foundation combined with tensile piles, which is composed of foundation concrete and steel tensile piles standing underneath. Consists of foundation concrete and steel tensile piles standing underneath,
A steel tensile pile is composed of a connecting rod, a connecting ring attached to the upper end of the connecting rod, and a resistance plate attached to the lower end of the connecting rod, and the resistance plate is substantially vertical from the flat portion and both side ends thereof. And the lower end of the connecting rod is attached to the center of the vertical wall portion of the resistance plate flat portion,
A concrete foundation combined with a tensile pile, wherein an upper part of the connecting rod and a connecting ring are embedded in the foundation concrete. Consists of foundation concrete and steel tensile piles standing underneath,
A steel tensile pile is composed of a connecting rod, a connecting ring attached to the upper end of the connecting rod, and a resistance plate attached to the lower end of the connecting rod, and the resistance plate is formed by screwing a steel plate into a screw shape. As well as
A concrete foundation combined with a tensile pile, wherein an upper part of the connecting rod and a connecting ring are embedded in the foundation concrete. Consists of foundation concrete and steel tensile piles standing underneath,
The steel tensile pile includes a connecting rod, a connecting ring attached to the upper end of the connecting rod, two resistance plates having one end attached to the lower end of the connecting rod and extending laterally, and the two resistances. The lower end is attached to each other end of the plate, and the upper end is integrated at the upper side and consists of two auxiliary rods connected to the middle part of the connecting rod,
A concrete foundation combined with a tensile pile, wherein an upper part of the connecting rod and a connecting ring are embedded in the foundation concrete.   The tension pile combined concrete foundation according to any one of claims 1 to 4, wherein a plurality of tension piles are erected with respect to one foundation concrete.   The tensile pile combined concrete foundation according to any one of claims 2 to 5, wherein a reinforcing bar for fixing the tensile pile in the foundation concrete is inserted into the connecting ring at the upper end of the connecting rod.   After embedding the steel tensile pile according to any one of claims 1 to 6 in the center of the excavated root cutting hole, foundation concrete is embedded in the root cutting so as to embed the upper portion of the steel tensile pile. A method for constructing a concrete foundation combined with tensile piles, characterized by casting.   The steel tensile pile according to any one of claims 2 to 6 is embedded in the center of the excavated root cutting hole, and the reinforcing rod for fixing the tensile pile is attached to the connecting ring at the upper end of the connecting rod constituting the steel tensile pile. A method for constructing a concrete foundation combined with a tensile pile, wherein the foundation concrete is placed in the root cutting so as to embed an upper portion of the steel tensile pile after being inserted.

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